Description:(Taken directly from the application) The Equipment Core was established at the last competitive renewal of this Program Project to provide a means of centralizing the costs of major shared equipment used by multiple investigators and subprojects. The Equipment Core also concentrates the costs of equipment maintenance and upgrades, eliminating the difficulties in allocating these on a pro-rata basis to the various subprojects. The budget requested for the Equipment Core includes the costs of several new equipment items that would be purchased over the next three years to meet the combined goals of the Program, as well as the costs of ongoing service contracts on major equipment already in heavy use by Program scientists.